[BACKPORT 4.14.y v3 0/3] Candidates from Spreadtrum 4.14 product kernel

[BACKPORT 4.14.y v3 0/3] Candidates from Spreadtrum 4.14 product kernel

[Baolin Wang]

With Arnd's script [1] help, I found some bugfixes in Spreadtrum 4.14 product
kernel, but missing in v4.14.146:

513e1073d52e locking/lockdep: Add debug_locks check in __lock_downgrade()
957063c92473 pinctrl: sprd: Use define directive for sprd_pinconf_params values
87a2b65fc855 power: supply: sysfs: ratelimit property read error message

[1] https://lore.kernel.org/lkml/20190322154425.3852517-19-arnd@arndb.de/T/

Changes from v2:
 - Drop 2 unnecessary patches (patch 1 and patch 6) from v2 patch set.
 - Backport these patches to 4.19.y.

Changes from v1:
 - Drop 2 unnecessary patches (patch 1 and patch 4) from v1 patch set.
 - Add upstream commit id in change log for each stable patch.

David Lechner (1):
  power: supply: sysfs: ratelimit property read error message

Nathan Chancellor (1):
  pinctrl: sprd: Use define directive for sprd_pinconf_params values

Waiman Long (1):
  locking/lockdep: Add debug_locks check in __lock_downgrade()

 drivers/pinctrl/sprd/pinctrl-sprd.c       |    6 ++----
 drivers/power/supply/power_supply_sysfs.c |    3 ++-
 kernel/locking/lockdep.c                  |    3 +++
 3 files changed, 7 insertions(+), 5 deletions(-)

-- 
1.7.9.5

[BACKPORT 4.14.y v3 1/3] locking/lockdep: Add debug_locks check in __lock_downgrade()

[Baolin Wang]

From: Waiman Long <longman@redhat.com>

[Upstream commit 513e1073d52e55b8024b4f238a48de7587c64ccf]

Tetsuo Handa had reported he saw an incorrect "downgrading a read lock"
warning right after a previous lockdep warning. It is likely that the
previous warning turned off lock debugging causing the lockdep to have
inconsistency states leading to the lock downgrade warning.

Fix that by add a check for debug_locks at the beginning of
__lock_downgrade().

Reported-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Reported-by: syzbot+53383ae265fb161ef488@syzkaller.appspotmail.com
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Link: https://lkml.kernel.org/r/1547093005-26085-1-git-send-email-longman@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
---
 kernel/locking/lockdep.c |    3 +++
 1 file changed, 3 insertions(+)

diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 565005a..5c370c6 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -3650,6 +3650,9 @@ static int reacquire_held_locks(struct task_struct *curr, unsigned int depth,
 	unsigned int depth;
 	int i;
 
+	if (unlikely(!debug_locks))
+		return 0;
+
 	depth = curr->lockdep_depth;
 	/*
 	 * This function is about (re)setting the class of a held lock,
-- 
1.7.9.5

[BACKPORT 4.14.y v3 2/3] pinctrl: sprd: Use define directive for sprd_pinconf_params values

[Baolin Wang]

From: Nathan Chancellor <natechancellor@gmail.com>

[Upstream commit 957063c924736d4341e5d588757b9f31e8f6fa24]

Clang warns when one enumerated type is implicitly converted to another:

drivers/pinctrl/sprd/pinctrl-sprd.c:845:19: warning: implicit conversion
from enumeration type 'enum sprd_pinconf_params' to different
enumeration type 'enum pin_config_param' [-Wenum-conversion]
        {"sprd,control", SPRD_PIN_CONFIG_CONTROL, 0},
        ~                ^~~~~~~~~~~~~~~~~~~~~~~
drivers/pinctrl/sprd/pinctrl-sprd.c:846:22: warning: implicit conversion
from enumeration type 'enum sprd_pinconf_params' to different
enumeration type 'enum pin_config_param' [-Wenum-conversion]
        {"sprd,sleep-mode", SPRD_PIN_CONFIG_SLEEP_MODE, 0},
        ~                   ^~~~~~~~~~~~~~~~~~~~~~~~~~

It is expected that pinctrl drivers can extend pin_config_param because
of the gap between PIN_CONFIG_END and PIN_CONFIG_MAX so this conversion
isn't an issue. Most drivers that take advantage of this define the
PIN_CONFIG variables as constants, rather than enumerated values. Do the
same thing here so that Clang no longer warns.

Link: https://github.com/ClangBuiltLinux/linux/issues/138
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
---
 drivers/pinctrl/sprd/pinctrl-sprd.c |    6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/pinctrl/sprd/pinctrl-sprd.c b/drivers/pinctrl/sprd/pinctrl-sprd.c
index 6352991..83958bd 100644
--- a/drivers/pinctrl/sprd/pinctrl-sprd.c
+++ b/drivers/pinctrl/sprd/pinctrl-sprd.c
@@ -159,10 +159,8 @@ struct sprd_pinctrl {
 	struct sprd_pinctrl_soc_info *info;
 };
 
-enum sprd_pinconf_params {
-	SPRD_PIN_CONFIG_CONTROL = PIN_CONFIG_END + 1,
-	SPRD_PIN_CONFIG_SLEEP_MODE = PIN_CONFIG_END + 2,
-};
+#define SPRD_PIN_CONFIG_CONTROL		(PIN_CONFIG_END + 1)
+#define SPRD_PIN_CONFIG_SLEEP_MODE	(PIN_CONFIG_END + 2)
 
 static int sprd_pinctrl_get_id_by_name(struct sprd_pinctrl *sprd_pctl,
 				       const char *name)
-- 
1.7.9.5

[BACKPORT 4.14.y v3 3/3] power: supply: sysfs: ratelimit property read error message

[Baolin Wang]

From: David Lechner <david@lechnology.com>

[Upstream commit 87a2b65fc855e6be50f791c2ebbb492541896827]

This adds rate limiting to the message that is printed when reading a
power supply property via sysfs returns an error. This will prevent
userspace applications from unintentionally dDOSing the system by
continuously reading a property that returns an error.

Signed-off-by: David Lechner <david@lechnology.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
---
 drivers/power/supply/power_supply_sysfs.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/power/supply/power_supply_sysfs.c b/drivers/power/supply/power_supply_sysfs.c
index eb5dc74..2ccaf4f 100644
--- a/drivers/power/supply/power_supply_sysfs.c
+++ b/drivers/power/supply/power_supply_sysfs.c
@@ -91,7 +91,8 @@ static ssize_t power_supply_show_property(struct device *dev,
 				dev_dbg(dev, "driver has no data for `%s' property\n",
 					attr->attr.name);
 			else if (ret != -ENODEV && ret != -EAGAIN)
-				dev_err(dev, "driver failed to report `%s' property: %zd\n",
+				dev_err_ratelimited(dev,
+					"driver failed to report `%s' property: %zd\n",
 					attr->attr.name, ret);
 			return ret;
 		}
-- 
1.7.9.5

Re: [BACKPORT 4.14.y v3 1/3] locking/lockdep: Add debug_locks check in __lock_downgrade()

[Waiman Long]

On 9/25/19 6:01 AM, Baolin Wang wrote:
> From: Waiman Long <longman@redhat.com>
>
> [Upstream commit 513e1073d52e55b8024b4f238a48de7587c64ccf]
>
> Tetsuo Handa had reported he saw an incorrect "downgrading a read lock"
> warning right after a previous lockdep warning. It is likely that the
> previous warning turned off lock debugging causing the lockdep to have
> inconsistency states leading to the lock downgrade warning.
>
> Fix that by add a check for debug_locks at the beginning of
> __lock_downgrade().
>
> Reported-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
> Reported-by: syzbot+53383ae265fb161ef488@syzkaller.appspotmail.com
> Signed-off-by: Waiman Long <longman@redhat.com>
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Linus Torvalds <torvalds@linux-foundation.org>
> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Will Deacon <will.deacon@arm.com>
> Link: https://lkml.kernel.org/r/1547093005-26085-1-git-send-email-longman@redhat.com
> Signed-off-by: Ingo Molnar <mingo@kernel.org>
> Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
> ---
>  kernel/locking/lockdep.c |    3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
> index 565005a..5c370c6 100644
> --- a/kernel/locking/lockdep.c
> +++ b/kernel/locking/lockdep.c
> @@ -3650,6 +3650,9 @@ static int reacquire_held_locks(struct task_struct *curr, unsigned int depth,
>  	unsigned int depth;
>  	int i;
>  
> +	if (unlikely(!debug_locks))
> +		return 0;
> +
>  	depth = curr->lockdep_depth;
>  	/*
>  	 * This function is about (re)setting the class of a held lock,

Apparently, there are 2 such patches in the upstream kernel - commit
513e1073d52e55b8024b4f238a48de7587c64ccf and
71492580571467fb7177aade19c18ce7486267f5. These are probably caused by
the fact that there are 2 places in the code that can match the hunks.
Anyway, this looks like it is applying to the wrong function. It should
be applied to __lock_downgrade. Though it shouldn't harm if it is
applied to the wrong function.

Cheers,
Longman

Re: [BACKPORT 4.14.y v3 1/3] locking/lockdep: Add debug_locks check in __lock_downgrade()

[Baolin Wang]

On Wed, 25 Sep 2019 at 22:05, Waiman Long <longman@redhat.com> wrote:
>
> On 9/25/19 6:01 AM, Baolin Wang wrote:
> > From: Waiman Long <longman@redhat.com>
> >
> > [Upstream commit 513e1073d52e55b8024b4f238a48de7587c64ccf]
> >
> > Tetsuo Handa had reported he saw an incorrect "downgrading a read lock"
> > warning right after a previous lockdep warning. It is likely that the
> > previous warning turned off lock debugging causing the lockdep to have
> > inconsistency states leading to the lock downgrade warning.
> >
> > Fix that by add a check for debug_locks at the beginning of
> > __lock_downgrade().
> >
> > Reported-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
> > Reported-by: syzbot+53383ae265fb161ef488@syzkaller.appspotmail.com
> > Signed-off-by: Waiman Long <longman@redhat.com>
> > Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> > Cc: Andrew Morton <akpm@linux-foundation.org>
> > Cc: Linus Torvalds <torvalds@linux-foundation.org>
> > Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
> > Cc: Peter Zijlstra <peterz@infradead.org>
> > Cc: Thomas Gleixner <tglx@linutronix.de>
> > Cc: Will Deacon <will.deacon@arm.com>
> > Link: https://lkml.kernel.org/r/1547093005-26085-1-git-send-email-longman@redhat.com
> > Signed-off-by: Ingo Molnar <mingo@kernel.org>
> > Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
> > ---
> >  kernel/locking/lockdep.c |    3 +++
> >  1 file changed, 3 insertions(+)
> >
> > diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
> > index 565005a..5c370c6 100644
> > --- a/kernel/locking/lockdep.c
> > +++ b/kernel/locking/lockdep.c
> > @@ -3650,6 +3650,9 @@ static int reacquire_held_locks(struct task_struct *curr, unsigned int depth,
> >       unsigned int depth;
> >       int i;
> >
> > +     if (unlikely(!debug_locks))
> > +             return 0;
> > +
> >       depth = curr->lockdep_depth;
> >       /*
> >        * This function is about (re)setting the class of a held lock,
>
> Apparently, there are 2 such patches in the upstream kernel - commit
> 513e1073d52e55b8024b4f238a48de7587c64ccf and
> 71492580571467fb7177aade19c18ce7486267f5. These are probably caused by
> the fact that there are 2 places in the code that can match the hunks.
> Anyway, this looks like it is applying to the wrong function. It should
> be applied to __lock_downgrade. Though it shouldn't harm if it is
> applied to the wrong function.

Ah, I noticed there are 2 commits with the same commit message, though
513e1073d52e55b8024b4f238a48de7587c64ccf patch did not change the
__lock_downgrade(), which is really confusing. This patch
(513e1073d52e55b8024b4f238a48de7587c64ccf) did the right thing, and
71492580571467fb7177aade19c18ce7486267f5 patch should be applied to
__lock_downgrade.

I'll backport commit 71492580571467fb7177aade19c18ce7486267f5 too in
future. Thanks.

-- 
Baolin Wang
Best Regards